关于对孟子E章《利用Repeater控件显示主－从关系数据表》的一点补充

 

有的网友在问怎样显示子表的前N条记录，下面是我的做法：
C#
ASPx文件：
<% @ Page language = " c# "  Codebehind = " WebForm13.aspx.cs "  AutoEventWireup = " false "  Inherits = " test1.WebForm13 "   %>
<% @ Import Namespace = " System.Data "   %>

<! DOCTYPE HTML PUBLIC  " -//W3C//DTD HTML 4.0 Transitional//EN "   >
< HTML >
     < HEAD >
         < title > WebForm13 </ title >
         < meta name = " GENERATOR "  Content = " Microsoft Visual Studio .net 7.1 " >
         < meta name = " CODE_LANGUAGE "  Content = " C# " >
         < meta name = " vs_defaultClientScript "  content = " JavaScript " >
         < meta name = " vs_targetSchema "  content = " http://schemas.microsoft.com/intellisense/ie5 " >
     </ HEAD >
     < body MS_POSITIONING = " GridLayout " >
         < form id = " Form1 "  method = " post "  runat = " server " >
             <!--  父Repeater开始  -->
             < asp:repeater id = " parentRepeater "  runat = " server " >
                 < itemtemplate >
                     < b >
                         <% # DataBinder.Eval(Container.DataItem, " au_id " )  %>
                     </ b >
                     < br >
                     <!--  子Repeater开始  -->
                     < asp:repeater id = " childRepeater "  runat = " server "  datasource = ' <%# getrow((DataRowView)Container.DataItem,1)%> ' >
                         < itemtemplate >
                             <% # DataBinder.Eval(Container.DataItem,  " [\ " title_id\ " ] " ) %>
                             < br >
                         </ itemtemplate >
                     </ asp:repeater >
                     <!--  子Repeater结束  -->
                 </ itemtemplate >
             </ asp:repeater >
             <!--  父Repeater结束  -->
         </ form >
     </ body >
</ HTML >
cs文件：
using  System;
using  System.Collections;
using  System.ComponentModel;
using  System.Data;
using  System.Drawing;
using  System.Web;
using  System.Web.SessionState;
using  System.Web.UI;
using  System.Web.UI.WebControls;
using  System.Web.UI.HtmlControls;
using  System.Data.SqlClient;

namespace  test1
{
    /**//**//**//// <summary>
    /// WebForm13 的摘要说明。
    /// </summary>
    public class WebForm13 : System.Web.UI.Page
    {
        protected System.Web.UI.WebControls.Repeater parentRepeater;
    
        private void Page_Load(object sender, System.EventArgs e)
        {
            // 在此处放置用户代码以初始化页面
            string cnnString = @"server=(local);database=pubs;uid=sa;pwd=sa";
            SqlConnection cnn = new SqlConnection(cnnString);
            SqlDataAdapter cmd1 = new SqlDataAdapter("select * from authors",cnn);

            //创建填充 DataSet.
            DataSet ds = new DataSet();
            cmd1.Fill(ds,"authors");

            // 为Titles表创建 DataAdapter
            SqlDataAdapter cmd2 = new SqlDataAdapter("select * from titleauthor",cnn);
            cmd2.Fill(ds,"titles");

            // 创建 Authors 表和 Titles 表之间的关系.
            ds.Relations.Add("myrelation",
                ds.Tables["authors"].Columns["au_id"],
                ds.Tables["titles"].Columns["au_id"]);

            // 绑定Authors到父Repeater
            parentRepeater.DataSource = ds.Tables["authors"];
            Page.DataBind();

            cnn.Close();
            cnn.Dispose();

        }

        Web 窗体设计器生成的代码Web 窗体设计器生成的代码#region Web 窗体设计器生成的代码
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
            //
            InitializeComponent();
            base.OnInit(e);
        }
        
        /**//**//**//// <summary>
        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {    
            //this.parentRepeater.DataBinding += new System.EventHandler(this.parentRepeater_DataBinding);
            this.Load += new System.EventHandler(this.Page_Load);

        }
        #endregion

        protected DataRow[] getrow(DataRowView drv,int num)
        {
            DataRow[] dr=drv.Row.GetChildRows("myrelation");

            if(dr.Length>num)
            {
                DataRow[] drtemp=new DataRow[num];
                for(int i=0;i<num;i++)
                {
                    drtemp[i]=dr[i];
                }
                return drtemp;
            }
            else
                return drv.Row.GetChildRows("myrelation");
        }
    }
}